Tractor for agricultural purposes

Abstract

A tractor for agricultural purposes, particularly for seedbed preparation, which comprises an engine of thirty or more kilowatts' power, a frame having two frame parts which are movable relative to each other about the frame's longitudinal axis, an axle extending from each side of each frame part which mounts on common wheel supports two tandem wheels having pneumatic tires mounted thereon. Each wheel is driven directly by its own hydraulic motor which is energized by a common hydraulic pump which, in turn, is driven by a diesel motor. The latter also drives via a gear box PTOs extending outwardly between wheels fore and aft and is the power source for two lifting devices, also extending outwardly between wheels fore and aft. The weight of the tractor is about forty kilograms per kilowatt engine power. Each lifting device has at its coupling points, a lifting capacity of at least one thousand kilograms.

Having described my invention, what I claim as new to be secured by Letters Patent of the United States is: 
     
       1. A tractor for agricultural purposes particularly for seedbed preparation, comprising an engine with a power of at least thirty kilowatts, a frame, eight wheels at least two of which are power driven wheels, at least one lifting device and at least one power take-off shaft, characterized in that the weight of the tractor is about forty kilograms per kilowatt engine power, the engine power being directly transferable to the power take-off shaft of the tractor, and the power output of said engine being so arranged to provide the lifting device at its coupling points with a lifting power of at least one thousand kilograms, and a cabin for the tractor's operator which has a width substantially equal to the overall width of the tractor and a horizontal length which is about one-half the overall length of the tractor and is above at least two of said wheels other than the forward or rear wheels of said wheels. 
     
     
       2. A tractor as claimed in claim 1, characterized in that the tractor has a length of about five meters. 
     
     
       3. A tractor as claimed in claim 1, characterized in that its length in millimeters is between two and three times the lifting power in kilograms of said lifting device at its coupling points. 
     
     
       4. A tractor as claimed in claim 3, characterized in that the tractor has a lifting device with a lifting power at its coupling points of more than two thousand kilograms. 
     
     
       5. A tractor as claimed in claim 1, characterized in that the tractor comprises at least four power driven wheels. 
     
     
       6. A tractor as claimed in claim 1, characterized in that the weight of the tractor is about two thousand kilograms, the power of the engine is about sixty kilowatts and the length of the tractor measured from the coupling points of its lifting device to its other end is about five meters. 
     
     
       7. A tractor for agricultural purposes, particularly for seedbed preparation, comprising an engine with a power of at least thirty kilowatts, a frame, eight wheels at least two of which are power driven wheels, at least one lifting device and at least one power take-off shaft, characterized in that the weight of the tractor is about two thousand kilograms, the power of the engine is about sixty kilowatts and the overall length of the tractor measured from the coupling points of its lifting device to its other end is about five meters, and having an operator's cabin which has a horizontal length which is at least one-half of the distance from the front of the forward of said wheels to the rear of the rearmost of said wheels. 
     
     
       8. A tractor as claimed in claim 1, characterized in that the coupling points of said lifting device are, as viewed in side elevation, directly behind one wheel of said wheels, said one wheel being about one meter in diameter. 
     
     
       9. A tractor as claimed in claim 7, wherein its engine power is not less than sixty kilowatts and the tractor comprises tires mounted on said power driven tractor wheels each of which has a diameter of about two and one-half times its width. 
     
     
       10. A tractor as claimed in claim 7 which comprises a further lifting device, wherein the total lifting power of said two lifting devices at their coupling points is at least about four thousand kilograms. 
     
     
       11. A tractor as claimed in claim 10, wherein one said lifting device is disposed at the tractor's front and the other said lifting device is at its rear. 
     
     
       12. A tractor as claimed in claim 11, comprising a further power take-off shaft, one said power take-off shaft being provided at tractor's front and the other at its rear. 
     
     
       13. A tractor as claimed in claim 7, wherein said wheels comprise two further power driven wheels, each of said wheels having a diameter of about one meter, said lifting device providing lifting power at its coupling points of at least three thousand kilograms. 
     
     
       14. A tractor as claimed in claim 7, wherein said lifting device is a three-point lifting device which provides lifting power at its coupling points of about one and one-half times the tractor's weight. 
     
     
       15. A tractor as claimed in claim 14, wherein the diameter of each said power driven wheels is about two times its width. 
     
     
       16. A tractor as claimed in claim 14, comprising a drive means for each said wheel, said drive means comprising light weight hydraulic motors. 
     
     
       17. A tractor as claimed in claim 14, wherein said frame is comprised substantially entirely of light weight hollow beams. 
     
     
       18. A tractor as claimed in claim 17, wherein said beams consist of tubular steel. 
     
     
       19. A tractor as claimed in claim 16, comprising axles for said wheels, wherein said hydraulic motors are directly connected to the axle of their corresponding wheel. 
     
     
       20. A tractor as claimed in claim 19, wherein the front side of said cabin extends rearwardly from near one of the tractor's said wheels mounted on a forward axle of said axles. 
     
     
       21. A tractor as claimed in claim 20, wherein said frame has two relatively movable frame parts and said cabin extends at least in part above a said frame part which is movable with respect to said cabin. 
     
     
       22. A tractor as claimed in claim 21, wherein, viewed from side elevation, said cabin extends above at least part of three of said wheels which are aligned parallel to the tractor's longitudinal axis. 
     
     
       23. A tractor as claimed in claim 22, wherein said rear wheels are movable up and down relative to said cabin. 
     
     
       24. A tractor as claimed in claim 19, wherein the length of the cabin, measured in the direction of the tractor's straight forward movement, is about two meters. 
     
     
       25. A tractor as claimed in claim 24, wherein internal height of said cabin is about one hundred, ninety centimeters. 
     
     
       26. A tractor as claimed in claim 14, characterized in that the tractor is provided with a ballast weight, said ballast weight being connectable to said lifting device. 
     
     
       27. A tractor as claimed in claim 26, wherein said ballast weight comprises means for connecting a wagon or implement to it. 
     
     
       28. A tractor as claimed in claim 15, wherein the diameter of each said power driven wheel is about one meter. 
     
     
       29. A tractor as claimed in claim 19, wherein each said wheel has a tire mounted thereon and the total of the added widths of all said tires is at least about two hundred, forty centimeters. 
     
     
       30. A tractor as claimed in claim 28, wherein the free space underneath the tractor is about sixty centimeters. 
     
     
       31. A tractor as claimed in claim 29, wherein each of said tires contacts the surface with substantially the same pressure. 
     
     
       32. A tractor as claimed in claim 29, wherein said wheels are contained in four tandem wheel sets. 
     
     
       33. A tractor as claimed in claim 32, wherein the total of the added widths of all tires on the front said wheel sets is at least about one hundred, twenty centimeters. 
     
     
       34. A tractor as claimed in claim 29, comprising a further lifting device, one said lifting device extending forward between front said wheels and the other said lifting device extending to the rear between rear said wheels, the total of the added widths of all tires of the tractor being at least one hundred, twenty centimeters per said lifting device.